Earthquakes are located on plate boundaries as shown by the grey shaded areas on the diagram above.
Causes of Earthquakes
An earthquake is caused when two plate tectonic plates push together or try to slide against each other. As the plates move friction stops the plates from moving past each other. This leads to a build up of pressure. Eventually the pressure gets too much and the plates move which causes an earthquake.
Key terminology
·Magnitude – how strong an earthquake is ·Richter scale – the scale on which the strength of the earthquake is measured ·Focus – the place deep in the earth where the rocks are moving ·After-shock – smaller earthquakes after the main, large one ·Seismometer – an instrument to measure the strength of the earthquake ·Epicentre – the point at the surface above the focus Primary and Secondary Effects ·Primary effect – are the immediate damage caused by the quake, such as collapsing buildings, roads and bridges, which may kill people. ·Secondary effect – the after-effects of the earthquake oFires oTsunami oLandslides oDisease and famine
The distribution of Earthquakes
Earthquakes are located on plate boundaries as shown by the grey shaded areas on the diagram above.
Causes of Earthquakes
An earthquake is caused when two plate tectonic plates push together or try to slide against each other. As the plates move friction stops the plates from moving past each other. This leads to a build up of pressure. Eventually the pressure gets too much and the plates move which causes an earthquake.
Key terminology
· Magnitude – how strong an earthquake is
· Richter scale – the scale on which the strength of the earthquake is measured
· Focus – the place deep in the earth where the rocks are moving
· After-shock – smaller earthquakes after the main, large one
· Seismometer – an instrument to measure the strength of the earthquake
· Epicentre – the point at the surface above the focus
Primary and Secondary Effects
· Primary effect – are the immediate damage caused by the quake, such as collapsing buildings, roads and bridges, which may kill people.
· Secondary effect – the after-effects of the earthquake
o Fires
o Tsunami
o Landslides
o Disease and famine